Malicious PDF — malware analysis report

Static analysis result for SHA-256 c305871fc214ecff…

MALICIOUS

PDF

80.4 KB Created: 2021-09-09 07:22:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0e4593edadd81352741472ec0d98e2e8 SHA-1: 78a523a7e09b18b313a7b92b51307920a700ea51 SHA-256: c305871fc214ecffaf31aabd84a8bf2ed5370e9bd4f59fb21613698e70de610c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple external URLs, some hosted on compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support the conclusion that this PDF is designed to distribute or facilitate access to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8255

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://inwebjor.ru/uplcv?utm_term=bus+ultimate+simulator+mod+apk PDF link annotation
    • http://zlhk.ru/upload_picture/file/84106819273.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/fanunewoxawoboxefojumasaw.pdfIn PDF document text
    • https://media-get.ru/userfiles/files/tubevudegejekasafez.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/161345717e3ac2---vexefawafi.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/44019973837.pdfIn PDF document text
    • http://origo.ws/userfiles/file/genufuvogibodiwi.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/dcce42b174698e23d7c621b9ed32ed1a/widemadutoga.pdfIn PDF document text
    • http://investin-khj.ir/ckfinder/userfiles/files/zibozina.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/gizaxusolebawuvupozirig.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/nixitaxisovusuz.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210904000308.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/dojorexojibifug.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/xanaf.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137890ee4613---77164245292.pdfIn PDF document text
    • http://konberdbio.com/upload/files/15586219691.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/45756489823.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/22561840078.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/riganipore.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6a506920f---6277827248.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/vomanolujezonuk.pdfIn PDF document text
    • https://mimpidia.com/contents/files/tofuxebuj.pdfIn PDF document text
    • https://viscom.bg/uploads/wysiwyg/files/vimegusofadizipiguge.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///zonulugosapoz.pdfIn PDF document text
    • https://civilkontroll.hu/uploads/file/40511322978.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/99111269846.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA84 19204 bytes
SHA-256: f0e9c7e56b5a529464b416982842722d6982f09230892864204e33d8a446cd55
font_01_sfnt_off00010caa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CAA 10696 bytes
SHA-256: 2c71c09a77cd6a91ffeed1d646694a081e64c35bfba23ba99ce18811ed383636
font_02_sfnt_off00012543.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12543 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1